Add Schema Diff to GitLab CI in 60 Seconds

🚀 One config, zero friction

Copy this into your repo as .gitlab-ci.yml or let the wizard auto-detect your schema files.

# .gitlab-ci.yml
stages:
  - validate

schema-diff:
  stage: validate
  image: node:20-alpine
  variables:
    SCHEMA_PATH: "db/schema.sql"
    DIALECT: "postgres"
    POST_MR_COMMENT: "true"
    FAIL_ON_BREAKING: "true"
  before_script:
    - apk add --no-cache git curl jq
  script:
    - git fetch origin $CI_MERGE_REQUEST_TARGET_BRANCH_NAME
    - git show origin/$CI_MERGE_REQUEST_TARGET_BRANCH_NAME:$SCHEMA_PATH > /tmp/schema_base.sql
    - node ci/schemalens-diff.js /tmp/schema_base.sql $SCHEMA_PATH --dialect=$DIALECT --format=markdown --output=/tmp/report.md
    - cat /tmp/report.md
  rules:
    - if: $CI_PIPELINE_SOURCE == "merge_request_event"
      changes:
        - "**/*.sql"
  artifacts:
    paths:
      - /tmp/report.md
    expire_in: 1 week

⚡ Generate my GitLab CI config Download .gitlab-ci.yml

💬 What your team sees in every merge request

SchemaLens Bot

commented 2 minutes ago

🔍 SchemaLens Schema Diff Report

🟢 Tables Added	1
🔴 Tables Removed	0
🟡 Tables Modified	2
⚠️ Breaking Changes	1
📊 Risk Score	42/100 (Medium)

ALTER TABLE users
  ADD COLUMN email_verified_at TIMESTAMP;

Why GitLab teams use SchemaLens

🛡️ Block breaking changes before merge

Dropped columns, removed indexes, and altered constraints fail the pipeline before they reach production.

💬 Native MR comments

Reviewers see the diff summary directly in the merge request — no external dashboards needed.

📦 Artifact reports

Every pipeline attaches a full markdown report for compliance docs, audits, or offline review.

⏭️ Smart skip saves CI minutes

The job only runs when .sql files change, so unrelated merges don't waste runner time.

Get it running in 3 steps

Open the GitLab CI wizard

The wizard auto-detects SQL files from your public GitHub or GitLab repo and selects the right dialect.

Copy the generated config

Paste it into .gitlab-ci.yml at the root of your repo. Adjust SCHEMA_PATH if your schema lives elsewhere.

Open your next merge request

SchemaLens compares the target branch schema against your branch and posts the result as an MR comment.

Ready to add schema diff to your GitLab repo?

It takes 60 seconds and works with PostgreSQL, MySQL, SQLite, SQL Server, and Oracle.

⚡ Generate GitLab CI config Other platforms

Add schema diff to your GitLab repo